Guide to Design Criteria for Bolted and Riveted Joints Second Edition
Riveted Joints
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Transcript of Riveted Joints
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Riveted Joints
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The fastenings (i.e. joints) may be classified into the following two groups :1. Permanent fastenings, and2. Temporary or detachable fastenings.
Introduction
The permanent fastenings are those fastenings which can not be disassembled without destroying the connecting components. The examples of permanent fastenings in order of strength are soldered, brazed, welded and riveted joints.The temporary or detachable fastenings are those fastenings which can be disassembled without destroying the connecting components. The examples of temporary fastenings are screwed, keys, cotters, pins and splined joints.
Rivet parts
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The function of rivets in a joint is to make a connection that has strength and tightness. The strength is necessary to prevent failure of the joint. The tightness is necessary in order to contribute to strength and to prevent leakage as in a boiler or in a ship hull.
Method of Riveting
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Lap joints
Butt joints cover platemain plate
Types of Riveted Joints
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Repeating group
Boiler joints (pressure joints)Repeating group
Inner cover plate
outer cover plateStructural joints
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Multiple rows
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long pitch
back pitch
diagonal pitch
short pitch
intermediate pitch
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Efficiency:
compares the strength of the joint with that of solids plates
P0P0
Efficiency = P1/P0
P1P1
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(1) Shearing (at connector)
(2) Tearing (of plate)
t
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(3) Bearing (of plate)
(4) Unlikely to occur
if the distance from the edge of the plate to the connector is large enough (1.75-2 times the diameter of the connector)
b
12
3.25
in calculation: 11/16 in.rivet holeD D
2
2
2( )4
2 (11/16) 88004
6533.5 lb.
d
(1) Rivet capacity (shearing of rivet and bearing failure)
s sP AShearing:
D
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3.25
(1) Rivet capacity (shearing of rivet and bearing failure) (cont’) b = 19 ksi
2( )
7 112( ) 19000
16 1611429.7 lb.
ttd
(2) Tearing capacity (tension failure of plate) t = 11 ksi
tP
bearing:b b bP A
11 7(3.25 ) 11000
16 1612332 lb.
tearing:
t t tP A
Hence the strength of the repeating section is 6533.5 lb per 3.25 in.
3.25”
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2
4
DF p
6533.50.418 41.8 %
3.25 (7 /16) 11000
6533.5 lb. per 3.25sP
2 6533.56 lb
4 3.25
Dp D
2(15 12) 6533.56(15 12)
4 3.25p
134 psi.p
Internal pressure
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(1) Preliminary calculation: load that can transmitted by one rivet (shear or bearing)
(2) Possible method of failure
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30060 MPa
5650
130 MPa5
40080 MPa
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b
t
d = 20.5 mm
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P-19.8 kN
19.8 kN
Row 1 (has 1-rivet)
19.8 kN
single shear
main plate
cover plate
19
P-37.3 kN
37.3 kN
P-26.7 kN
26.7 kN
Row 1 (has 1-rivet)
Hence strength of row-1 is 19.8 kN
main plate
cover plate
main plate
cover plate
crash in the main plate
37.3 kN
37.3 kN
P
crash in the cover plate
26.7 kN
26.7 kN
P
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Row 2 (has 2-rivets)
19.8 kN
59.4 kN
double shear
2 x 19.8 kN
19.8 kN
39.6 kN
P-99 kN
Shear strength at row-2 is
2 39.6 79.2 kN 2 x 19.8 kN
2 x 19.8 kN
2 x 19.8 kN
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crushing at cover plate
53.4 kN
4 26.7 106.8 kN
19.8 kN
P-126.6 kN4 x 26.7 kN
73.2 kN
2 x 26.7 kN
One possible bearing strength at row-2 is
2 x 26.7 kN
Row 2 (has 2-rivets)crushing at main plate
37.3 kN One possible bearing strength at row-2 is2 37.3 74.6 kN
19.8 kN
P-94.4 kN2 x 37.3 kN
37.3 kN
57.1 kN
37.3 kN
Hence strength of row 2 is 74.6 kN
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Row 3 (has 2-rivets)
Hence strength of row 3 is also 74.6 kN2 x 37.3
kN
37.3 kN
37.3 kN
crushing at main plate
4 x 26.7 kN
2 x 26.7 kN
2 x 26.7 kN
crushing at cover plate
2 x 19.8 kN
2 x 19.8 kN
double shear
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Total rivet capacity
19.8 kN74.6 kN 74.6 kN
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Tearing at row 1 of main plate Tearing at row
2 of main plate
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19.8 kN 74.6 kN 74.6 kN
Row 1 Row 2Row 3 80 MPa
14 mm
180 mm
20.5 mm
t
t
p
d
main plate1P
180 mmp t
main plate
19.8 kN
2P80 MPat
main plate
19.8 kN
37.3 kN
37.3 kN
3P80 MPat
1 ( ) tP p d t (180 20.5) 14 80 178.6 kN
2 ( 2 ) 19.8 kNtP p d t
175.5 kN
3 ( 2 ) 19.8 74.6 kNtP p d t 250.1 kN
Tearing capacity of main plate
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Tearing capacity of cover plate
P
P
Row 1 Row 3Row 2
19.8 kN
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79.2 111.2
190.4 kNcP
P
Row 1 Row 3Row 2
19.8 kN
outer cover plate
19.8 kN
19.8 kN
19.8 kN
9.9 kN
9.9 kN
79.2 kN
80 10 (180 2 20.5)
111.2 kN
80 MPat
inner cover plate
180 mmp
10 mmt20.5 mmd
( 2 )tP t p d
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Rivets failure: 169.0 kN
Tearing of main plate: 175.5 kN
Tearing of cover plate: 190.4 kN
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Assume each rivet carries a load proportional to its resisting shear area
1/2
1/2
1
1
2
2
2
Totally 9 shear areas:
the average load transmitted by 1 shear area is 36 / 9 4 kipssP
12-5 STRESSES IN BEARING-TYPE CONNECTIONS
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the average shearing stress is
Row1 Row2 Row3
4 kips
3/ 8 in
1/ 2 in 4 kips
4 kips
3/ 8 in
3/ 8 in
1/ 2 in
the maximum average bearing stress is
8=17.07 ksi
1 15( )
2 16
bb
P
td
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4=5.80 ksi
15/ 4 ( )4 16
sP
d
15 in
16d
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15 116 2
3610.2 ksi
(8 )t
15 116 22
36 4
(8 )
10.45 ksi
t
main plate (Row 2)
36 kips 2 kips
2 kips
main plate (Row 1)
36 kips
main plate (Row 3)
36 kips8 kips
8 kips
2 kips
2 kips
15 116 22
36 20
(8 )
5.23 ksi
t
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Upper cover plate
16 kips4 kips
4 kips
2 kips
2 kips
4 kips
Lower cover plate
20 kips4 kips
4 kips
2 kips
2 kips
2 kips
2 kips
4 kips
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Lower cover plate
20 kips4 kips
4 kips
2 kips
2 kips
2 kips
2 kips
4 kips
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Lab joints (ต่�อทาบ) Butt joints (ต่�อชน)
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shearing capacity of 1-rivet2( / 4)sP d
295( 19 / 4) N
26.935 kN
bearing capacity of 1-rivet
( )b bP td
220(8 19) N
33.44 kNupper plate1P
250 mmL t
9 26.935 kN
242.42 kNrivetP
Total rivets capacity
1.5 mmhole rivetd d 20.5 mm
1 ( )t holeP t L d
140 8 (250 20.5) N 257 kN
Row1
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1.5 mmhole rivetd d
2 26.94 kN ( 2 )t holeP t L d
140 8(250 2 20.5) N
2 261 kNP
upper plate2P
250 mmL 26.94 kN
tRow2
3 3 26.94 kN ( 3 )t holeP t L d
140 8(250 3 20.5) N
Row3
t
3P26.94 kN
26.94 kN
26.94 kN3 291.9 kNP
Hence the joint capacity is 242.42 kN
Efficiency =242.42 kN
86.6%140 8 250 N
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(1.5,4)
(1.5,0)
(1.5,-4)
(4.5,4)
(-4.5,0)
(-4.5,4)
(-4.5,-4)
(4.5,0)
(4.5,-4)
(-1.5,0)
(-1.5,4)
(-1.5,-4)
28.82.4 kips
12dxP
38.43.2 kips
12dyP
38.4 4.5 kips.inT
172.8 kips.in
Twisting moment
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ให้�น�สิ�ต่พยายามท�าโจทย�ข้�อ 1220 ถึ�งข้�อ 1240 ให้�ได้�นะครั�บ
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สิ�าห้รั�บรัอยต่�อแบบ friction type ให้�ค�ด้แบบเด้"ยวกั�บรัอยต่�อแบบ bearing type ยกัเว�นไม�ต่�องค�านวณค�าห้น�วยแรังแบกัทาน (Bearing
stress) ท"&เกั�ด้ข้�'นรัะห้ว�าง bolt และ plate
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strength of butt weld
allowable stress lenght of weld thickness of the thinner plate
Butt Weld
allowable stress allowable stress of base metal
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tO45
Othroat sin 45 0.707t t
Fillet Weld
base on AISC, for E70 electrodes, A36 steel 21 ksiallow
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E70 : 21 ksi
14.9 kips/in.q t
3 1 5
8 16 16t
3/8
Ans
4.66 kips/in.
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Ans
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Centroid:
Torsional couple:
Polar moment of inertia:
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